Corn is grown in most U.S. States, but production is concentrated in the Heartland region (including Illinois, Iowa, Indiana, eastern portions of South Dakota and Nebraska, western Kentucky and Ohio, and the northern two-thirds of Missouri). Iowa and Illinois, the top corn-producing States, typically account for slightly more than one-third of the U.S. crop.

Because of provisions in the Federal Agriculture Improvement and Reform Act of 1996, corn acreage in the United States has increased from a government-mandated low of 60.2 million planted acres in 1983. The Act permitted farmers to make their own crop planting decisions based on the most profitable crop for a given year. While the number of feed grain farms (those that produce corn, sorghum, barley, and/or oats) in the United States has declined in recent years, the acreage per corn farm has risen. Moreover, the number of large corn farms (with more than 500 acres) has increased over time, while the number of small corn farms (with less than 500 acres) has fallen.

Corn production has risen over time, as higher yields followed improvements in technology (seed varieties, fertilizers, pesticides, and machinery) and in production practices (reduced tillage, irrigation, crop rotations, and pest management systems).

Strong demand for ethanol production has resulted in higher corn prices and has provided incentives to increase corn acreage. In many cases, farmers have increased corn acreage by adjusting crop rotations between corn and soybeans, which has caused soybean plantings to decrease. Other sources of land for increased corn plantings include cropland used as pasture, reduced fallow, acreage returning to production from expiring Conservation Reserve Program contracts, and shifts from other crops, such as cotton.

Corn has food, feed, and industrial uses. It is a major component of livestock feed. Feed use, a derived demand, is closely related to the number of animals (cattle, hogs, and poultry) that are fed corn. The amount of corn used for feed also depends on the crop's supply and price, the amount of supplemental ingredients used in feed rations, and the supplies and prices of competing ingredients.

As ethanol production increases, the supply of ethanol coproducts will also increase. Both the dry-milling and wet-milling methods of producing ethanol generate a variety of economically valuable coproducts, the most prominent of which is distillers dried grains with solubles (DDGs), which can be used as a feed ingredient for livestock. Each 56-pound bushel of corn used in dry-mill ethanol production generates about 17.4 pounds of DDGs. In the United States, cattle (both dairy and beef) have been the primary users of DDGS as livestock feed, but larger quantities of DDGs are making their way into the feed rations of hogs and poultry.

Corn is also processed for human consumption and other industrial uses. Food, seed, and industrial uses (FSI) of corn account for about one-third of domestic utilization. During processing, corn is either wet or dry milled depending on the desired end products:

The market for food made from corn has grown in recent years with the expanding Latin American population in the United States. In the future, food uses for corn are expected to expand at the rate of population growth. Research is continuing to expand the various industrial uses for corn and corn byproducts.

Farmers may be eligible to receive government payments that support or protect their income. These include production flexibility contract payments, marketing loans, disaster aid, conservation payments, and crop insurance. (See the Policy page for more information.) Government programs have been instrumental in the development of the HFCS and fuel alcohol markets. Import fees, duties, and import quotas on sugar have made HFCS an economical alternative. Recent Federal environmental laws have paved the way for greater use of corn in fuel alcohol production.

Corn is the largest component of global coarse grain trade (including corn, sorghum, barley, oats, rye, millet, and mixed grains), generally accounting for about two-thirds of the volume over the past decade. The United States is the world's largest corn producer and currently exports about one-fifth of annual production. (See the Trade page for more information.)